Area Forecast Discussion
Issued by NWS Chicago, IL

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
FXUS63 KLOT 152332

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
632 PM CDT Fri Sep 15 2017

217 PM CDT

Through Saturday...

No significant weather is expected through the period. Expect
southerly winds and warm temperatures to continue across the area
on Saturday. High temperatures into the mid 80s is expected area-
wide under mainly sunny skies.



127 PM CDT

Saturday night through Friday...

After a period of relatively quiet weather, the southern stream will
become more unsettled as the high amplitude long wave upper level
pattern trends toward more zonal flow.  By Saturday night, the upper
trough over the west will move out over the central plains.  The
parent upper low over the Canadian Rockies will also progress east,
helping to break down the upper ridge over the east. Temperatures
will trend closer to more seasonable levels of upper 70s to lower
80s by Sunday. As the upper level pattern trends to more zonal, a
more active southern stream will set up with a series of weak
shortwaves rippling through the fast wswly-wly flow aloft brings
periodic chances for showers and thunderstorms for much of next
week.  The longer range guidance is coming into decent agreement on
a stronger shortwave impacting the region Monday evening, so have
increased PoPs to likely for that time.  Otherwise, keep periodic
slight chance to chance PoPs through much of the longer term
forecast period.


For the 00Z TAFs...

No significant forecast concerns through next 36 hours.

Warm, well mixed boundary layer conditions will continue to
support south winds though the period. Lake breeze boundary
currently east of ORD/MDW is not expected to move across either
airport. Some increase in patchy high clouds are possible into
Saturday, with VFR conditions prevailing through the forecast



130 PM CDT

High pressure will remain in place over the eastern CONUS through
the weekend and the early part of next week while low pressure
deepens over the central plains. This will result in persistent,
generally southerly winds over Lake Michigan. The low will lift
through the Upper Midwest to Hudson Bay Sunday night while a
trailing cold front pushes across Lake Michigan, turning winds to
north to northeast on Monday. High pressure will then build over
the upper Great Lakes Monday. Another low will develop over the
central plains by midweek allowing winds to veer to the south to





WWW.YOUTUBE.COM/NWSCHICAGO is the U.S. government's official web portal to all federal, state and local government web resources and services.